FDA Approves RSV Vaccine for Pregnant Individuals as Prevention Tool

On August 21, 2023, the United States Food and Drug Administration (FDA) approved Abrysvo, a respiratory syncytial virus (RSV) vaccine. The drug aims to prevent illness in infants under six months by vaccinating pregnant individuals between 32 and 36 weeks of gestation.

These indications add to the previous FDA approval, which allowed the vaccine to be administered to adults ages 60 and older.

According to the FDA press release, this new approval is based on multiple clinical studies that highlight the safety and efficacy of the vaccine in these patient populations. One study recruited 7,000 pregnant individuals, half getting the vaccine and the other half getting a placebo.

Infants whose pregnant parent got the vaccine had an 81.8% lower chance of severe lower respiratory tract disease within 90 days of birth. In addition, the risk of illness within 180 days was 69.4% less than the group receiving the placebo.

Looking closely at infants born to pregnant people vaccinated between 32 and 36 gestational weeks, researchers found a 91.1% reduction in severe lower respiratory tract diseases within 90 days of birth. In addition, the probability of lower respiratory tract diseases was nearly 35% lower.

In the 180-day time frame, the risk for any lower respiratory tract disease was 57.3% lower, and the risk of severe disease was 76.5% lower.

In addition, the vaccine was safe for these patient populations. The most common side effects were injection site pain, headache, muscle pain, and nausea. Although most patients did not have severe symptoms, slightly more patients receiving the vaccine experienced pre-eclampsia.

“RSV is a common cause of illness in children, and infants are among those at highest risk for severe disease, which can lead to hospitalization,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, in the press release. “This approval provides an option for healthcare providers and pregnant individuals to protect infants from this potentially life-threatening disease.”